Muffler



Feb. 4, 1930. R. A. MOORE MUFFLER Filed March 19.

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Patented Feb. 4, 1930 UNITED STATES PATENT OFFICE ROBERT A. MOORE, OF NEW YORK, N. Y., ASSIGNOR TO M & ENGINEERING CORPO- RATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK MUFFLER Application filed March 19, 1928. Serial No. 262,762.

This invention is an improvement in mufliers, and more particularly in a muffler designed to eliminate noise without back pressure, and to discharge the gases of combustion in a condition as nearly harmless as is possible.

The usual construction of mufliers is designed to elongate the individual discharges of burnt gases so that instead of individual and separated discharges under considerable pressure, there will be a continuous stream or discharge under light pressure.

Vith this object in view, an expansion chamber is provided, having means in the form of baffles or the like, to retard the flow of theburnt gases through the muffler, and to cool the gases by radiation. In substantially all of such constructions, the direct flow of the gases is impeded and restricted, so that a considerable back pressure is set up in the muffler.

In addition, the constituent gases are usually discharged in a more or less segregated condition, so that deleterious gases, such as carbon monoxide, are in a more or less condensed form, that is, in a massed condition, whereby such gases easily may separate and, being massed or condensed, are in a condition of greatest toxicity.

One of the primary objects of the present invention is the provision of a mufiier with a maximum efficiency as a silencer, and with the least possible resistance to the flow of the exhaust gases thereby to avoid back pressure.

Another object is the provision in such a muffler of means for thoroughly mixing the exhaust gases, and for diffusing the several gases throughout each other, so that theresulting mixture has a minimum deleterious action.

Another object is to provide a muffler of simple and inexpensive construction, the essential features of which are similar units, easily assembled into the completed structure. I

In the drawings forming a part hereof Fig. 1 is a plan view of the improved inulller with a part in section.

Figs. 2 and 3 are sections on the lines 22 and 33 of Fig. 1.

The present embodiment of the invention includes a tubular casing, circular in cross of each reducing section is split as shown at 7 to enable it to be clamped onto the pipe 5 or 6 as thecase may be. Ears 7 are provided at opposite sides of the split, and a bolt 8 passes through the ears, and is engaged by a nut to enable clamping of the small end of the section onto the pipe.

lVithin the casing is arranged mechanism for thoroughly mixing and intimately diffusing the exhaust gases, and for rapidly cooling the gases as they pass through the muffler. The said mechanism is composed of similar units, each of which is of spiral formation, and of a length covering a completecircumference of the casing interior. That is, each unit, when in place, has its ends in register, but offset longitudinally of the casing.

The units have overlying flanges 9 at their free ends, which are adapted to hook into similar flanges of-other units, thereby to con nect a series of units into a spiral vane of suitable length and substantially continuous from end to end. The said vane may be held in the casing in any suitable'manner, in the present instance the casing Wall being spirally grooved as indicated at 10, to receive the free outer edge of the vane.

Each of the units includes an imperforate marginal portion, the outer edge of which engages the groove 10, and the inner edge of which is provided with deflectors to be later described. When in place in the casing, the imperforate portion 11 of the connected units provides for an outer spiral passage extending the full length of the muffier casing, but

of much greater length on account of the spiral formation.

The imperforate portion of the units is of a width corresponding substantially to the excess in diameter of the mufller casing over the discharge pipes. That is, with a discharge pipe of two inches, for instance, the internal diameter of the mulfler casing will be four inches, and the imperforate portion of the vane will be one inch in radial width. Thus there is left a passage through the center of the mufiier, of a capacity substantially that of the capacity of the discharge pipe 5.

The inner edge of the imperforate portion of the mixing mechanism is provided with a plurality of sets of deflecting blades or.

' thereagainst, such gases will be deflected in a spiral direction onto the faces of an adjacent set.

The deflectors point toward the discharge I pipe 5 and while oflering but little impediment to the escape of the gases, they exert a cooling mixing action thereon, and change the course of travel of the gases toward the peripheral surface of the casing, and into.

. the spiral passage extending from end to end of the casing, and of substantially the capacity of the pipe 5. It will be apparent from the description that within the improved mufiler there are two passages, either 'ofwhich has the same capacity as the discharge pipe.

One is direct through the mufiler and in line with the discharge pipe, but having mechanism therein to break up the gases, and deflect them outwardly, and in such manner as to thoroughly mix andintimately diffuse said.

gases into a homogeneous mixture,'while at the same time offering a minimum of impediment to the flow thereof. It will be apparent that the vane may be made of a heat resistant material, if desired, from material that will not be atfected by the heat of the exhaust gases.

The blades of the set are so. arranged in the set, and the sets are so arranged with respect to each other, that each blade of each set deflects a part of the flow onto the'corresponding blade of the set immediately in rear. This arrangement causes the minor streams to interweave, so that intimate difiusion of the constituent gases of the exhaust discharge results, and consequent dilution of the deleterious gases. i

The exhaust is delivered from the mufile'r in a continuous stream, that is, without separate impulses, so that noise is eliminated. Since there is no restriction in the capacity of the engine discharge, and a minimum of obstruction to the direct flow of the exhaust gases through the muflier, back pressure is avoided. The elimination of back pressure provides for free working of the engine, and for a greater quantity of oxygen in the discharge.

All of these deflectors are so set with respect to the gas flow, that such flow impinges on the edge of the deflector, so that while the deflectors thoroughly cut up and change the direction of flow of the gases through the central passage, they offer little or no restriction to the flow. and do not in any way'restrict the capacity of the central passage, which has an aggregate capacity at least as great as that of the inlet of the mutfler.

The deflected portions of the gases impinge against the edge of other deflectors, which, in turn, separate the minor streams, deflecting portions thereof. Hence, there is frequently repeated alternating operations of splitting and deflection. The communication between the external spiral passage and the central direct passage is always free, so that the gases in both passages may freely intermix.

The constituent gases discharged from'the muflier are in a state of intimate diffusion, andthe deleterious gases are in a state of extreme dilution. An analysis of the gases at the inlet end and at the outlet end of the muflier indicate a material lessening of the carbon monoxide value, and a material increase in the oxygen value. This increase in oxygen is due to the easy working of the engine, because of the lack of back pressure, and materially assists in the dilution of the carbon monoxide. I

What is claimed as new is 1. ,A mufiler including a casing having an inlet and an outlet, andan internal spiral vane extending substantially the full length of the casing, said vane having a free inner edge'radially spaced from the axis of the casing to provide a direct axial passage open to the spiral passage formed by the casing and the vane, and blades extending into the axial passage and presenting their edges to the inlet of the casing, said blades being staggered from end to end of the casing.

2. A muffler including a casing having an inlet and/an outlet, and an internal spiral vane extending substantially the full length of, the casing, said vane having afree inner edge radially spaced from the axis of the casing to provide a direct axial passage for the combustion ases open to the spiral passage formed by the casing and the vane, and blades extending into the axial passage and presenting their edges to the inlet of the casing. said blades beingstaggered from end to end of the casing, each blade having a spiral m sses gases away from the axis sage formed by the casing and tbe'vane, and

blades extending into the axial passage and presenting their edges to the inlet of the casing, each blade having a spiral twist, and the blades being arranged in sets, with the blades of each set positioned to deflect said gases into impact with the edges of the corresponding blades of the succeeding set.

a. A mufiier including a casing having an inlet and an outlet, and an internal spiral vane extending substantially the full length of the casing, said vane having'a free inner edge radially spaced from the axis of the casing to provide a direct axial passage for the combustion gases open to the spiral'passage formed by the casing and the vane, and blades extending into theaxial passage and presenting their edges to the inlet of the easing and designed to split the combustion gases into streams, said blades being arranged in sets, the blades of each the streams deflected by the corresponding blades of the preceding set. I

5. A mufller including a casing having an inlet and an outlet, and an internal spiral of the casing,

vane extending substantially the full length of the casing, said vane having a free inner edge radially spaced from the axis of the casing tr, provide a direct axial passage for the combustion gases 0 n to the spiral passage forrnecl by the caslng and the vane, and blades extending into the axial passage and presenting their edges to theinlet of the easing and designed to split the combustion gases into streams, said blades being arranged in sets, the blades of each set positioned to split the streams deflected by the corrcs nding blades of the preceding set, the vanebging composed of similar a set of blades.

6. A rnufier including a casing having an units, each unit carrying inlet and an outlet, and an internal spiral vane extending substantially the full length of the casing, said vane having a free inner edge radially. spaced from the axis of the casing to provide a direct axial passage open to the spiral passage formed by the casing and the vane, said vane being composed of similar units, each unit carrying a set of blades with their edges presented to the inlet of the casing, said blades being staggered from end to end of the casing.

7. A mufier including a casing having an inlet and an outlet, and an internal spiral vane extending substantially the full length said vane having a free inner of the casing, .edge radiallyspaced from. the axis of the casset positioned to s lit edge radially spaced from the axis of the casing to provide a direct axial passage for the combustion gases open to the spiral passage formed by the casing and the vane, said vane being composed of similar units, each unit carrying a-set of blades with their edges presented to the inlet of the casing, each blade having aspiral twist to deflect the gases into impact with the edge of the corresponding blade of'a succeeding unit I 8. A mufier including a casing having a reduced axial inlet, and an internal spiral vane extending substantially the full length said vane having a free inner ing to provide a direct axial passage open to the spiral passage formed by the casing and the vane, and of a cross sectional capacity not less than that of the inlet, and blades extending from said edge into the axial passage and presenting their edges to the inlet, said blades being staggered from end to end of the casin 9. mufiler including a casing having a reduced axial inlet, and an internal spiral vane extending substantially the full length of thev casing, said vane having a free inner edge radially spaced from the axis of thecasing to provide a direct axial passage open to the spiral passage formed by the casing and the vane, and of a cross sectional capacity not less than that of the inlet, and blades extending from said edge into the axial passage and presenting their edges to the inlet, each blade having a spiral twist to deflect the gases away from the axis of the mufiler.

10. A mufier including a casing having a reduced axial inlet, and an internal spiral vane extending substantially of the casing, I edge radially spaced from the axis of the casing to provide a direct axial passage open to the spiral passage formed by the casing and the vane, and of a cross sectional capacity not less than that of the inlet, said blades extending from said edge into the axial passage and presenting their edges to the inlet, each blade having a spiral twist, and the blades being arranged in sets, with the blades of each set 0- sitioned to deflect the gases into impact with the edges of the corresponding-blades oi the succeeding sets,

ll. A mufier including a casing having a reduced axial inlet, and an internal spiral vane extending substantially the full length of the casing, said vane having a free inner edge radially spaced from the axis of the casing to provide a direct axial passage open to the spiral passage formed by the casing and the vane, and of'a cross sectional capacity not less than that of the inlet, the vane being composed of similar units, each unit carrying a set of blades, with their edges presented to the inlet of the casing, each blade having a spiral twist, and the blades of each set posithe full length said vane having a free inner ill tioned to deflect the gases into impact with the edges of the corresponding blades of the succeeding set.

A 12. A muffler including an expansion casing having a reduced inlet, said casing providing an anal assage for the combustion gases of substantially the capacity of the inlet, and blades extending into the axial passage and presenting their edgesto the inlet 0 of the casing, said blades being staggered y from end to end of the casing, and each having a spiral twist. p

13. A muflier including an expansion casing having a reduced inlet, said casing having 15 means therein to provide a spiral passage for z the combustion gases extending substantially from end to end of the casing at the periphery thereof, and an axial: passage of substantially the same capacity as the inlet, and having in the axial-passage a plurality of sets of blades presenting theiredges to the inlet, whereby to split the flow of combustion gases into a multiplicity of streams.

14. A muflier including an expansion casing as having a reduced inlet, said casing having means therein to provide a spiral passage for the combustion gases extending substantial- 1y from end to'end of the casing at the periphery thereof, and an axial passage of suba0 stantially the same capacity as the inlet, and

having in the axial passage a plurality of sets of blades presenting their edges to the inlet, whereby tosplit the flow of combustion gases into a multiplicity of streams, each blade hav- 35 ing a spiral twist to deflect the gases in a generally spiral direction.

Signed at BMW York, in the county of New I York and State of New York, this 17th day of March, A; D. 1928.

to I ROBERT MOORE. 

